Geoeg montanus



(No Model.)

G. MONTANUS.

RESISTANCE REGULATOR FOR ELEGTRIG GURRENTS.

No. 372,860. Patented Nov. 8, 1887.

WITNESSES INVENTOR ATTORNEYS.

N. Pnws-Phom-um n w. Wnhinglon, n4 0.

UNITED STATES PAT NT OFFICE.

GEORG MONTANUS, OF FRANKFORT-ON-THE-1VIAIN, GERMANY.

RESISTANCE-REGULATOR FOR ELECTRIC CURRENTS.

SPECIFICATION forming part of Letters Patent No. 372,860, dated November 8, 1887.

Application filed June 19, 1886. Serial No. 205,660. (No model.) Patented in Germany January 30, 1886, No. 37,086.

.To all whom it may concern:

Be it known that I, GEORG MONTANUS, a subject of the Emperor of Germany, and residing at Frankfort-on-the-Main, Germany, have invented new and useful Improvementsin Resistance Regulators for Electric Currents, (for which a patent has been obtained in Germany, No. 37,086, dated January 30, 1886,) of which the following is a specification.

The object of my invention is to provide a new and improved switch and resistance regulator especially adapted for electrical dental motors and other similar electric motors.

The invention consists of a number of wires forming a rheostat and connecting a number of springs with the terminals of the motor and of a ring having a segmental flange which, when turned, connects the first of said number of wires with any desired number of the remaining wires.

The invention also consists of various parts and details and combinations of the same, as will be fully described hereinafter, and then pointed out in the claims.

Reference is to be had to the. accompanying drawings, forming a part of this specification, in which similar letters of reference indicate corresponding parts in all the figures.

Figure 1 is an end elevation of my improvement. Fig. 2 is a longitudinal central section of the same on the line wmof Fig. 1. Fig. 3 is aside elevation of an electrical dental motor provided with my improvement, and Fig. 4. is a diagram showing the connections.

Heretofore switch and resistance regulators for electric motors used for operating dental drills and similar tools were actuated by the foot of the operator; but such movement greatly impeded the work of the operator. In my present invention I obviate this inconvenience and place the regulator at the front end of the tube holding the tools and within easy reach of the operator s hand.

The resistance-switch A is preferably placed on the tool-holder B or on the flexible tube 0, in which rotates the tool-shaft, and is provided with a metal ring, M, turning loosely on the flanged pipe m, secured to the short tube H, of

vulcanite or other non-conducting material.

The tube H is slipped over the tool-holder B or into the flexible tube O,'and is provided with a number of springs, or n #91 11 the free ends of which project toward the ring M, which has a segmental flange, a, which overlaps and comes in contact with the free ends of the springs n n, 850., when the ring or sleeve M is turned on its axis on the flanged pipe m. A stop, S, limits the motion of the ring or sleeve M, which can be turned to bring its flange a in contact with one or more of the springs or n, &c., which are insulated from each other. The wire at is connected by an insulated copper wire, b, with the positive pole of the bat tery of the electric dental motor, while the other remaining springs, n n n a are each separately connected by a copper wire, 0, with the electro-magnet E and the negative pole of the battery, as clearly shown in Fig. 4. All the electric wires are brought together to form a cable, K, which is wound around the flexible tube 0, carrying the tool-shaft.

The resistance-wires in the cable K form a rheostat, and it will be seen that when the segmental flange a of the ring M is in contact with only the first spring, n, the electric circuit is broken; but when the ring M is turned so that its flange a is in contact with the next and succeeding springs, 12 n", &c., the circuit is completed through one or more of these springs connected with the resistance-wires, and'the resistance of the circuit is inversely according to the number of wires through which the cur rent is switched. The motor D can thus be started or stopped by turning the ring M, and the speed of the motor D is regulated according to the number of springs 12/11 91 a connected by means of the flange a with the first spring, a.

It will be understood that my invention is applicable not only to electric dental motors,

but also .to other electrical machines.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. In a resistance-regulator for dental drills and other analogous electrical apparatus, the combination, with a motor, of an insulatingtube, H, a series of springs attached thereto and connecting with the terminal wires of the motor, as specified, and a rotatable ring, M, having a segmental flange adapted to come in contact with one or more of said springs when the ring is turned on its axis, substantially as with one or more of said springs. and thus specified. either break the circuit or complete it through 2. In aresistanoe'regnlator for dental drills, one or more wires, substantially as specified. the combination, with a motor, the flexible In testimony whereofI have signed my name [5 5 tube 0, and the drill-tool holder 13, ofthe nonto this specification in the presence of two subconducting or insulating tube H, applied to the scribing witnesses. latter, the series of springs n n of, 850., at

tached to the tube and connected with the GEORG MONTANUS' terminals of the motor in the manner specified, \Vitnesses: 10 the ring M, having a segmental flangea, which, ALVEs'rO S. HOGUE, when said ring is rotated, Will come in contact JOSEPH PATRICK. 

